Process for making cord



m 1949. f L. G. E ING ET'AL 2 466,80

rnocnss FOR uni m com) Filed Jan. 29, 1947 /NVENTOR$ Zesus 6. hznwnva I fRAN/r. 5595/0; i

- flTTOR/VEY Patented Apr. 12, 1949 Leslie 1G. Henning, Cleveland, and Frank L. .Ses-

sions, Lakewood, Ohio; said rHenning :assignor to: said Sessions Application January 29, 1947, S eriaFNo. 725,118

."11 Claims.

This -invention;-relaltes to improvements in textile cordsor the like and processes of making-and treating them. Briefly, it relates ,to the making and treatment of cords, which are 'made of cotton or other vegetable "stapl fiber yarns, to improve their strengths, elastic characteristics, toughness and durability,-and increase their ability to 'withstand high, dry temperature without injurious efiects.

In our patent application, Serial 'No. 548,378, filed August '7, 1944, entitled "Iextile cord and "process of making it? we have described and claimed textile, staple fiber cord and a process of making it which includes certain yarn, thread and cord constructions and twisting operations and wet-stretching and dry-setting of the finished cord at a prescribed stretched length.

In carrying out our present invention we prefer to treat cords that have been made in accordance with the teachings of our above mentioned patent application, although our tests indicate that any staple -fiber cotton cord that has not been treated to make it impervious to moisture, may be improved by subjecting it to the process steps "herein described.

By our present invention, staple fiber "cotton cord issubjected to processing operations as describedin the following numbered paragraphs.

Treatment of icord (1) A "completely twisted cord is immersed in an aqueous wetting rand/or "shrinking liquid, or an aqueous wetting, shrinking and impregnating liquid solution wherein it is {thoroughly wet,

preferably :urea, ;or urea. and :hexamethylenetetramine, and .sulphonated :esters of dicarboxylic acids, and, if desired, accelerator preferably composed of about .seven .and one-half (71/ parts of .diammonium acid phosphate and .one

(1) .partiof hexamethylenetetramine, such chemicals being decomposed or transformed at the temperatue to which .the cord .is to "be subsequently "subjected as described in paragraph (3 below.

(2) The shrunken, saturated 'cord resulting from operation (-1=) fis wet stretched to a length between about 5185 percent and about 96 per cent of the length-of the'original singles yarns which 'were -embodied inthe cord, and theWet-st-retched cord is dried while being prevented from com tr acting from its stretched length. During this drying operation the temperature should {be kept below the curing temperature described in *pa-r- 'agraph -63) below] if 'the wetting solution icontamed-decomposablematerials.

(3) The dry-setcord resulting from the we'tshrinking, impregnating, Wet-'stretching anddrysetting, --operations described in the above par-agraphs (1) and ('2), is heat'shrunk or heatshrunk and heat cured if the wet-shrinking-i-and wet-stretching solution also contained -heat-decomposable, iinpregnatimg:, curing material. The temperature for this shrinking and curing heat treatment isaboveabout eighty degrees-680% cen- "tigrade-and preferablyisabout one hundred forty degrees centigrade. The heat treatment should --be carried out while the cord is without substantial tension and is in a slack, contractile state, 'for the time found necessary to heat- :S'hliIi-kbi heat-shrink and 'heatcure the cord,'ibut not long-enough to scorch'or otherwise damage 'it. Higher temperature demands shorter time.

The accompanying drawing shows, diagrammatically, means for progressively and continauously performing the operation of our process.

clear understanding of the drawings can "best be had by referring to the above three numbered paragraphs (1), (2) and (3) under the caption Treatment ofcordi Fig. '1 of the drawing is asdhematicdiagram of the entire apparatus; and Fig.2 isa side "view of conical stretching rolls l-l-H, this view being taken from the plane indicated by line =2, 2, in Fig.1.

In the drawing, the cord is designated by the reference letter A. It is drawn from the supply reel '3 by cord-driving rolls C--C. The reel B --is provided with an adjustable hub brake D for varying the tension upon th cord. The-rolls-C may 'be driven by an electric motor E, the speed of which may be varied bya motor starting and speed controlling 'rheostat or other suitable means. The cord A is delivered by rolls i-nto the wetting and shrinking or wetting, shrinking and impregnating solution contained in the tank G. It passes through the liquid solution in the tank G in a slack, contractile state and is withdrawn by the conical, stretching rolls H-H, which may bedriven'by an electric'motor I, the speed of which may be varied by a -motor starting and speed controlling rheostatJ orother suitable-means.

Since the length of the cord contracts as it passes through the liquid solution in the tank G, the cord must be withdrawn from the tank at a slower speed than that at which it is delivered into it. The delivery and withdrawal speeds of the cord may readily be adjusted so as to keep the cord in the desired slack contractile state while being shrunk in passing through the liquid solution. After being stretched to the desired length, the cord is prevented from contracting while it is being drawn through the drying oven K by the cord-driving rolls L-L and is dried by hot, dry air which may be heated in the stove M and blown through the oven K by the blower N. The rolls L-L, are also driven by the electric motor I at the peripheral speed that is required to keep the tension of the cord substantially constant in its passage through the drying oven so that the cord will be dry-set at substantially the desired stretched length when it emerges from the oven, drawn by the rolls L-L.

From the rolls LL, the cord is delivered substantially in a slack contractile state into the heat-shrinking and heat-curing oven and, since the length of the cord contracts as it passes through the heated oven the cord must be withdrawn from the oven at a slower speed than that at which it is delivered into it. The corddelivery rolls P-P may be driven by an electric motor, Q, the speed of which ma be controlled by a motor starting and speed controlling rheostat R. Thus the speed of the cord may be adjusted so that the cord will be allowed to shrink while passing through the oven.

From the cord-delivery rolls P-P the finished cord may be delivered to and wound upon a suitable spool or container S upon which it is preferably wound under uniform light tension limited by a friction slip clutch.

It will be understood that some of the operations may be performed in separate apparatus, operated and controlled entirely independently of th apparatus used for performing others of the operations. For instance, the wet-shrinking, wetstretching and dry-setting operations may be performed continuously in one apparatus and the dry-set cord instead of being delivered directly to the heat-shrinking and heat-curing apparatus, may be spooled for storag before the heatshrinking or heat-shrinking and heat-curing operations are performed in independently driven and controlled apparatus.

- If desired the cord after being heat-shrunk in oven 0, may be wound under a light tension upon a cone or container and be further heatcured by electronic or other heat-treatment.

The time for which the cord may be subjected to a given high temperature for being shrunk and/or cured without injury, depends upon the construction of the cord, the kind of material of which it is made, the composition of the liquid in which it was shrunk, or, shrunk and impregnated, and the atmospheric conditions to which the cord is subjected in the oven. We have found that staple fiber cotton cord after being shrunk in clear water, wet-stretched and dry-set in the manner described in the above paragraphs (1) and (2) will be heat-shrunk by being subjected for about a minute to a temperature of about 140 centigrade. Such a cord will not be injured if it is subjected to such a temperature for hours or is subjected to higher temperatures for short periods.

Our tests have shown that the resulting elastic characteristics a cord will have after it has been heat-shrunk or heat-shrunk and heat-cured as described in the above paragraph (3) depend upon the ratio which the length of the wet-stretched, dry-set cord of the above paragraph (2) bears to the length of the original singles yarns embodied in the cord. In general, the elongation of the finished heat-shrunk or heat-shrunk and heat-cured cord at a given intermediate load will be greater, and its breaking strength will be less if the wet-stretching and dry-setting operations performed upon it have resulted in the length of the dry-set cord being relatively low in the range of stretched lengths prescribed in the above paragraph (2) to wit, between about eighty-five per cent and about ninety-six per cent (96%) of the length of the original singles yarns embodied in the cord, than they will be if these operations have resulted in the length of the cord being in a higher part of the prescribed range. The length at which the cord should be dry-set in order that it shall have desired stressstrain characteristics after being heat-shrunk and heat-cured may be established readily by trial and test.

While cord that has been shrunk in clear water, wet-stretched, and dry-set as above described in paragraphs (1) and (2) is further improved by the heat-shrinking operation which is described in paragraph (3), our tests indicate that when a liquid wetting, shrinking and curing solution containing urea has been used, the cords strength, elasticity and ability to withstand high temperature are greatly increased. It appears that the urea in solution impregnates the lumens of the fibers of the cord and that when the urea-impregnated dry-set cord is subjected to a temperature above about one hundred thirty degrees centigrade the urea is decomposed, certain gases being driven off, leaving in the lumens a residue of higher temperature resisting material. In any event, the cord is improved and becomes stronger, more elastic and more heat resistant than cord which has been shrunk in clear water. Still greater strength, elasticity and ability to withstand high temperature result from the use of urea and hexamethylenetetramine in the solution.

We have been unable to determine whether the urea or hexamethylenetetramine have chemically united with the cellulose of the fiber, but whatever the cause, the cords and consequently the fibers which compose them are greatly improved by the treatment described in the above paragraphs (1), (2) and (3).

Our test indicates that a solution of urea and hexamethylenetetramine in the proportions of about ten pounds, dry weight, of urea; about eight pounds, dry weight of hexamethylenetetramine; about sixteen (16) grams, dry weight, of sulphonated esters of dicarboxylic acids; and about sixteen hundred (1600) grains of an accelerator composed of seven and one-half (7 /2) parts of diammonium acid phosphate and one (1) part of hexamethylenetetramine, all dissolved in about seven gallons of water, is a superior lubricating liquid solution for wet-twisting threads and cords and for wet-shrinking and impregnating cords before they are wet-stretched and dry-set for heat-shrinking and curing. The shrinking and impregnating efiect of this solution on cotton cord and its fibers, respectively, is extremely rapid and complete.

The best results are assured when the yarns are saturated for wet-twisting into thread, the threads are saturated for wet-twisting into cord,

and the com lete cord is then processed as the scribed in paragraphs (1), (2) and (3).

Cords which have been processed as described in paragraphs (1) and (2) are substantially benefited by the heat-shrinking and heat-curing operations described in paragraph (3).

The following are data of actual tests that we have made of some staple fiber cotton cords that were treated by our process and of other cords that were not treated. by our process. The testswere all made upon a Scott 50 pound capacity single strand testing machine." They provide a convenient means for comparing critical characteristics of the cords whose data are given. The marked improvement in breaking strength and uniformity of elongation effected by our process are clearly shown by these test results.

inc. liquid solution of impregnating andcuring material, stretching it while wet to a length between about 85% and about 96% of the length of the original singles yarns embodied in the cord, drying the cord at its stretched length but not further stretching it and heat-shrinking and curing it without substantial tension at a temperature above about 80 oentigrade but short of the scorching temperature, for such time that the cord will be heat-shrunk and cured.

4. The process of treating textile natural vegetable staple fiber cord which includes shrinking and impregnating it without substantial tension in a liquid solution containing urea, stretching the shrunken cord While wet, drying it at its stretched length, but not further stretching it, and heat-shrinking and heat-curing it without s ple Cord and treatment Elongation at-- Breaking strength Kind of cotton and staple length 7 10 lbs. Break 22.5/5/3-Water wet-twisted Control Cord.

oi Urea. while wet n 5 22.5/5/3 Cord-Twisted shrunk (sec Treatment of Cord, paragraph (3)). 22.5/5/3Cord Twisted shrunk (see Treatment of Cord, paragraph (3)).

22.5/5/3Water wet-twisted Control Cord, 'wir' li'et't're'reiidjliii Cord, Water Shnmk wet-stretched (sec Treatment of Cord, paragraphs (1) and (2));

22.5/5/3-Water wet-twisted Control Cord; Wet-shrunk in Solution A (see footnote); see Treatment of Cord. paragraphs) (1) and (2); Heat-Shrunk wet with about per cent aqueous solution Wet-shrunk in same strength urea solution: Stretched with same urea solution (see Treatment oi Cord. paragraplfis (1)) and (2)); Heat-Shrunk (see Treatment of Cord, parawet with an aqueous solution containing about 22 per cent Urea and bout 15.5 per cent Hexamethylenetetramine; Wet-shrunk in same solution; Stretched while wet with same solution (see Treatment of Cord, paragraphs (1) and (2)); Heatwet with an aqueous solution oi urea, hexamethylenetetramine, sulphonated esters of dicarboxylic acids and an accelerator composed of about seven and one-half (7%) parts of Dlammonium A cid Phosphate and one (1) part of hexamethyleuetetramme; (see Treatment of Cord, paragraphs (1) and (2)); Heat- Per cent Per cent PMS" Staple Peruvian Pima. 75

5 5 5 Water .ldo 5.5 825 SEE --..-do.-s. if 8. 25

Nora: In re. Sample 3-Solution A is the same aqueous solution as is used in Sample No. 6.

Although we have described in considerable detail certain preferred procedures and solutions for the treatment of cords of the type described, it will be understood that variations and modifications in the composition of the treating solutions and in the processing steps may be made without departing from our invention. We do not, therefore, wish to be limited to the specific materials and process steps herein described but claim as our invention all embodiments thereof coming within the scope of the appended claims.

We claim:

1. The process of treating textile natural vegetable staple fiber cord which includes shrinking it without substantial tension in a liquid, stretching the shrunken cord While wet; drying it at its stretched length but not further stretching it, and heat-shrinking it without substantial tension at a temperature above about eighty degrees (80) centigrade.

2. The process of treating textile natural vegetable staple fiber cord which includes impregnating it in a solution of heat-decomposable impregnating and curing material, stretching it while wet, drying it at its stretched length but not further stretching it, and heating and curing it without substantial tension at a temperature at or above that at which said heat-decomposable material is decomposed.

3. The process of treating textile natural vegetable staple fiber cord which includes shrinking and impregnating it without substantial tension substantial tension at a temperature above about eighty degrees centigrade for such time that the cord will be heat-shrunk and heatcured.

5. The process of treating textile natural vegetable staple fiber cord which includes shrinking and impregnating it without substantial tension in a liquid solution containing hexamethylenetetramine, stretching the shrunken cord while wet, drying it at its stretched length but not further stretching it, and heat-shrinking and heat-curing it without substantial tension at a temperature above about eighty degrees (80) centigrade for such time that the cord will be heat-shrunk and heat-cured.

6. The process of treating textile natural vegetable staple fiber cord which includes shrinking and impregnating it without substantial tension in a liquid solution containing urea and hexamethylene-tetramine, stretching it while wet, drying it at its stretched length but not further stretching it, and heat-shrinking and heat-curing it without substantial tension at a temperature above about eighty degrees (80) centigrade and below the cord-scorching temperature for such time that the cord will be heat-shrunk and heatcured.

7. The process defined by claim 6 in which the liquid solution contains urea and hexamethylenetetramine in the proportions of about ten pounds, dry weight, of urea, about eight pounds, dry weight, of hexamethylenetetramine and about one gram, dry weight, of a penetrant or wetting agent such as sulphonated esters of dicarboxylic acids all dissolved in about seven gallons of water.

8. The process of making textile natural vegetable staple fiber cord as defined by claim 6 in which the liquid solution contains urea and hexamethylenetetramine in the proportions of about ten pounds, dry weight, of urea, about eight pounds, dry weight, of hexamethylene tetramine, about sixteen (16) grams dry weight, of a penetrant or wetting agent such as sulphonated esters of dicarboxylic acids, and about sixteen hundred (1600) grains of an accelerator such as one composed of seven and one-half (7 /2) parts of diammonium acid phosphate to one (1) part of hexamethylenetetramine, all dissolved in about seven gallons of water.

9. The process of treating textile natural ve etable staple fiber cord made of a plurality of original singles yarns of known length, which includes saturating and shrinking the cord in liquid while the cord is in a slack, contractile state; wet-stretching the wet-shrunken cord to a length between about eighty-five per cent (85%) and ninety-six per cent (96%) of the length of the original singles yarns embodied in the cord; drying the cord while it is being prevented from contracting from its stretched length; releasing the stretching tension; and heat-shrinking the dried cord at a temperature above about eighty degrees (80) C., but below the cord-scorching temperature while the cord is in a slack, contractile state.

10. The process of treating textile natural vegetable staple fiber cord made of a plurality of original singles yarns of known length, which includes saturating and shrinking the cord in a liquid solution containing heat-decomposable, impregnating, curing material while the cord is in a slack, contractile state; wet-stretching the shrunken cord to a length between about eightyfive per cent (85%) and ninety-six per cent (96%) of the original singles yarns embodied in the cord; drying the cord while it is being prevented from contracting from its stretched length; releasing the stretching tension; and heat-shrinking and heat-curing the dried cord at a temperature above about eighty degrees C., but below the cord-scorching temperature while the cord is in a slack, contractile state.

11. The process of treating textile natural vegetable staple fiber cord which includes (1) thoroughly wetting it in an aqueous wetting, shrinking and impregnating liquid solution; (2) allowing the cord to shrink while it is in a slack contractile state without tension while in the solution 'until the cord becomes limp and inert; (3) wet-stretching the shrunken cord resulting from operations (1) and (2) to a length between about eighty-five per cent and ninety-six per cent (96%) of the length of the original singles yarns which were embodied in the cord; (4) drying the wet-stretched cord while it is prevented from contracting from its stretched length; (5) releasing the stretching tension; and (6) heat curing the released cord at a temperature above about eighty degrees (80") C. but below the cord-scorching temperature.

LESLIE G. I-IENNING. FRANK L. SESSIONS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

